A couple of years ago, I posted that a Block Island shop had Dole Whip Floats. They used orange juice rather than pineapple juice though.
I've seen Orange Leaf yogurt shops that have pineapple yogurt. You can get it for takeout so this weekend, I'll be making my own Dole Whip Floats. My grocery store sells pineapple juice. Add some Disney park music and I'm all set.